288310-94-1Relevant academic research and scientific papers
Efficient Asymmetric Biomimetic Aldol Reaction of Glycinates and Trifluoromethyl Ketones by Carbonyl Catalysis
Cao, Jing,Cheng, Aolin,Liu, Tao,Song, Guanshui,Zhang, Kun,Zhang, Liangliang,Zhao, Baoguo,Zhao, Guoqing,Zhou, Qinghai
supporting information, p. 20166 - 20172 (2021/07/20)
The direct asymmetric aldol reaction of glycinates represents an intriguing and straightforward strategy to make biologically significant chiral β-hydroxy-α-amino-acid derivatives. But it is not easy to realize the transformation due to the disruption of the reactive NH2 group of glycinates. Inspired by the enzymatic aldol reaction of glycine, we successfully developed an asymmetric aldol reaction of glycinate 5 and trifluoromethyl ketones 4 with 0.1–0.0033 mol % of chiral N-methyl pyridoxal 7 a as the catalyst, producing chiral β-trifluoromethyl-β-hydroxy-α-amino-acid esters 6 in 55–82 % yields (for the syn-diastereomers) with up to >20:1 dr and 99 % ee under very mild conditions. The reaction proceeds via a catalytic cycle similar to the enzymatic aldol reaction of glycine. Pyridoxal catalyst 7 a activates both reactants at the same time and brings them together in a specific spatial orientation, accounting for the high efficiency as well as excellent diastereo- and enantioselectivities.
The effect of various zinc binding groups on inhibition of histone deacetylases 1-11
Madsen, Andreas S.,Kristensen, Helle M. E.,Lanz, Gyrithe,Olsen, Christian A.
, p. 614 - 626 (2014/03/21)
Histone deacetylases (HDACs) have the ability to cleave the acetyl groups of ε-N-acetylated lysine residues in a variety of proteins. Given that human cells contain thousands of different acetylated lysine residues, HDACS may regulate a wide variety of processes including some implicated in conditions such as cancer and neurodegenerative disorders. Herein we report the synthesis and ina vitro biochemical profiling of a series of compounds, including known inhibitors as well as novel chemotypes, that incorporate putative new zinc binding domains. By evaluating the compound collection against all 11 recombinant human HDACs, we found that the trifluoromethyl ketone functionality provides potent inhibition of all four subclasses of the Zn2+- dependent HDACs. Potent inhibition was observed with two different scaffolds, demonstrating the efficiency of the trifluoromethyl ketone moiety as a zinc binding motif. Interestingly, we also identified silanediol as a zinc binding group with potential for future development of non-hydroxamate classa I and classa IIb HDAC inhibitors.
Highly selective trifluoroacetic ester/ketone metathesis: An efficient approach to trifluoromethyl ketones and esters
Zhou, Yuhan,Yang, Dongmei,Luo, Gen,Zhao, Yilong,Luo, Yi,Xue, Na,Qu, Jingping
, p. 4668 - 4674 (2014/06/23)
A highly selective and atom efficient 'trifluoroacetic ester/ketone metathesis' has been sincerely witnessed. Enolizable alkyl (at least two non-hydrogen atoms) aryl ketones were found to react readily with ethyl trifluoroacetate under the promotion of NaH to afford trifluoroacetic ester/ketone exchange products, trifluoromethyl ketones (TFMKs), and aromatic acid esters, which were quite different from the general Claisen condensation products, 1,3-diketones. The outcome of the reaction between ketone and ethyl trifluoroacetate is strongly related to the structures of substrates, the steric congestion caused by alkyl group is in favor of the C-C bond cleavage. DFT investigation further disclosed that the metathesis reaction was a kinetically favored pathway. Using only a slight excess of cheap trifluoromethylation reagent, simple operation and mild conditions make it a practical method for preparation of TFMKs on large scale, as well as a new choice of converting aryl alkyl ketones to aromatic acid esters.
Synthesis of trifluoromethyl ketones via tandem Claisen condensation and retro-Claisen C-C bond-cleavage reaction
Yang, Dongmei,Zhou, Yuhan,Xue, Na,Qu, Jingping
, p. 4171 - 4176 (2013/06/05)
A highly efficient, operationally simple approach to trifluoromethyl ketones has been developed that builds on the use of a tandem process involving Claisen condensation and retro-Claisen C-C bond cleavage reaction. Enolizable alkyl phenyl ketones were found to react readily with ethyl trifuoroacetate under the promotion of NaH to afford trifluoroacetic ester/ketone exchange products, trifluoromethyl ketones, which were quite different from the general Claisen condensation products, β-diketones. This procedure uses readily available starting materials and can be extended to the preparation of perfluoroalkyl ketones in excellent yield.
A Weinreb amide approach to the synthesis of trifluoromethylketones
Rudzinski, Diandra M.,Kelly, Christopher B.,Leadbeater, Nicholas E.
supporting information, p. 9610 - 9612 (2012/10/29)
A novel route to access trifluoromethylketones (TFMKs) from Weinreb amides is reported. This represents the first documented case of the Ruppert-Prakash reagent (TMS-CF3) reacting in a constructive manner with an amide and enables synthesis of TMFKs without risk of over-trifluoromethylation.
Preparation of fluoroalkyl imines, amines, enamines, ketones, α-amino carbonyls, and α-amino acids from primary enamine phosphonates
Palacios, Francisco,Ochoa De Retana, Ana Maria,Pascual, Sergio,Oyarzabal, Julen
, p. 8767 - 8774 (2007/10/03)
A simple method for preparation of fluoroalkyl β-enaminophosphonates 1 from alkylphosphonates 2 and perfluoroalkyl nitriles 3 is reported. Olefination reaction of functionalized phosphates 1 with aldehydes gives α,β-unsaturated imines 5. Acid hydrolysis of these fluoroalkyl derivatives 5 affords α,β-unsaturated ketones 6, while their selective reduction with hydrides leads to the formation of allylamines 7, enamines 8, and saturated ketones 9 or amines 10. Selective oxidative cleavage of the carbon-carbon double bond of allylamines 7 gives fluorinated α-amino aldehydes 12, α-amino ketones 13, or α-amino acid derivatives 14.
Regioselective intramolecular oxidation of phenols and anisoles by dioxiranes generated in situ
Yang, Dan,Wong, Man-Kin,Yan, Zheng
, p. 4179 - 4184 (2007/10/03)
A novel method for regioselective oxidation of phenols and anisoles has been developed in which dioxiranes, generated in situ from ketones and Ozone, oxidize phenol derivatives in an intramolecular fashion. A series of ketones with electron-withdrawing groups, such as CF3, COOMe, and CH2Cl, were attached to phenols, anisoles, or aryl rings via a C2 or C3 methylene linker. In a homogeneous solvent system of CH3CN and H2O, oxidation of phenol derivatives 1-10 afforded spiro 2-hydroxydienones in 24-55% yields regardless of the presence of other substituents (ortho Me, meta Me or Br) on the aryl ring and the length of the linker. Experimental evidences were provided to support the mechanism that involves a regioselective π bond epoxidation of aryl rings followed by epoxide rearrangement and hemiketal formation.
